Dr. Sebastian Wolf

Cell Wall Signalling in Plants

The Cell Wall

The growth of plant cells is both limited and controlled by the physical properties of its extracellular matrix, the cell wall. The cell wall consist of a complex mixture of polysaccharides, proteins and other polymers which are extruded and assembled into a rigid, yet dynamic organized network. In addition to its role in growth control, the cell wall represents the plant`s first line of defence against pathogens and injury, is essential for the formation of tissues, is crucial for cell to cell signalling and determines the shape of cells and organs. In order to serve all of these functions, the wall has to be able to change its properties in relatively short time, highlighting the need for not only a regulated biosynthesis, but also for modification of the relevant molecules after their deposition. An important example for such a modification module is the de-methyl-esterification of the cell wall polysaccharide homogalacturonan, the most abundant form of pectin, by the ubiquitous plant enzyme pectin methylesterase.

Cell Wall Signalling

It is essential for all organisms to integrate signals form the extracellular matrix with intrinsic cues to coordinate development, growth, and behaviour. This is particularly important for plants, as their morphogenesis is mainly controlled by the properties of their rigid, yet dynamic, extracellular matrix, the cell wall. To control growth, but also to respond to extrinsic perturbations, cell wall state is constantly monitored and information must be conveyed to the cell interior in order to fine-tune the physico-chemical properties of the wall for optimal responses. However, very little is known about this cell wall-mediated signalling in plants.

Our main goal is to identify cell wall signalling pathways and to characterize the role of cell wall signalling in the maintenance of cellular mechanics, in the coordination of growth between cells, and in the adaption to environmental conditions. Using a variety of cell biological and genetic methods, we study how the cell wall controls signalling to the cell interior and characterize the consequences of these signalling processes at the cell and tissue level. In addition, using genetic screens and various biochemical approaches, we want to identify novel components of cell wall signalling to gain a molecular understanding of the cell wall and its function in the control of development adapted to environmental conditions.